This invention relates to a method and apparatus, in a blow-molding operation, for making a plastic fabricated product having a recessed portion. More particularly, it relates to a method of forming such a fabricated product and placing it into engagement with a separate sub-assembly to form a relatively tight union between the fabricated product and the sub-assembly.
While the present invention has broad application where it is desired to join, with a relatively tight union, a blow-molded fabricated product with a second, separately fabricated sub-assembly, a preferred application of the present invention is in the blow-molding fabrication of an overcap. An overcap is a blow-molded fabricated product which is either functional or decorative in design, or both, and is desired to fit over a closure for a container, such as the closure of a hair-care product. Heretofore there have been no overcaps which have been designed to grip tightly the container closure. Moreover, there have been no overcaps wherein the portion of the overcap designed to grip the container closure has been completely recessed within the body of the overcap itself. These deficiencies have given rise to a number of problems and disadvantages. Because of the loose-fitting nature of the prior art overcaps, the overcap and the closure become disassembled during shipment necessitating troublesome and expensive re-assembly of the two parts; the sales or promotional advantage arising from the overcap's remaining on the closure is lost because shortly after the packaged product is used --frequently with the first such use--the overcap separates from the closure and is discarded by the consumer. Where the overcap is small enough to swallow, its attractiveness combined with its loose-fitting nature posed obvious hazards to the small child. In addition, the lack of a completely recessed design distracts from the visual effect of the overcap. For example, not only is the outer portion of the overcap design, for example in the shape of a lemon, visible but its visual impact is lessened by a neck protruding down from the base of the lemon designed to loosely engage the closure. All these disadvantages of the prior art are minimized or completely eliminated by the use of the present method and apparatus.